Thin-film-coated substrate manufacturing methods having improved film formation monitoring and manufacturing apparatus

Abstract

The present invention is directed to providing thin-film-coated substrate manufacturing methods and apparatus that make it possible to manufacture large thin-film-coated substrates such as anti-reflection filters using relatively small production facilities. The thin-film-coated substrate manufacturing methods pertaining to the present invention area capable of producing thin films on substrates to be coated as large as the film formation area by using a film formation monitor or monitors placed outside of the film formation area or displaceably mobile therein, measuring the thickness of the monitor thin film or films formed on the film formation monitor or monitors, and controlling the film coating process based on the measured thickness of the monitor thin film or films. It is also capable of increasing the productivity of the manufacturing process through increased flexibility in the arrangement of substrate or substrates to be coated inside the film formation area.

We claim: 
     
       1. A thin-film-coated substrate manufacturing method that exposes at least one substrate to be coated during movement thereof through a film-forming particle beam, comprising steps of: providing at least one film-forming particle beam generating source for generating a film within a film-forming particle exposure area, said beam including a central axis;   moving the at least one substrate to be coated with a moving device along a pathway into the exposure area, said exposure area including a film formation area, said film formation area including a surface of the at least one substrate and a surface of said moving device;   providing at least one optical interference film formation monitor plate within the exposure area;   generating film-forming particles from the at least one generating source into the film-forming particle exposure area to form a monitoring film on the at least one film formation monitor plate and for coating a thin film on the at least one substrate;   continuously measuring a thickness and a refractive index of the monitoring film formed on the at least one film formation monitor plate by using an optical interference measuring device; and   coating the thin film on the at least one substrate, the step of coating including a step of continuously monitoring the thickness of the monitoring film and coating the thin film in accordance with the thickness and the refractive index of the monitoring film, wherein   the at least one film formation monitor plate is either (i) affixed within the exposure area and outside the film formation area and outside said central axis of said beam; or   (ii) displaceable within the exposure area and within said central axis of said beam, whereby a correlation of the film thickness disposed on the at least one affixed or displaceable monitoring plate relative to a film thickness disposed on the at least one substrate is substantially maximized, wherein     a distance from the at least one film formation monitor plate to one generating source is in a range of 0.9 times or more of a minimum distance from the one generating source to the closest point thereto in the film formation area and in a range of 1.1 times or less of a maximum distance from the one generating source to the farthest point therefrom in the film formation area; or   a first angle formed by a straight line connecting a location of the at least one film formation monitor plate and the at least one generating source and a film-forming particle beam axis is in a range of twice or less than a second angle formed by a straight line connecting the at least one generating source and the farthest point therefrom in the film formation area and the film-forming particle beam axis thereof.   
     
     
       2. The thin-film-coated substrate manufacturing method according to claim 1, further comprising the step of providing the at least one generating source includes limiting the exposure area by interposing a film formation area limiting element between the at least one generating source and the at least one substrate. 
     
     
       3. The thin-film-coated substrate manufacturing method according to claim 1, wherein the at least one substrate is a row of substrates. 
     
     
       4. The thin-film-coated substrate manufacturing method according to claim 1, wherein the at least one substrate is multiple rows of substrates. 
     
     
       5. The thin-film-coated substrate manufacturing method as claimed in claim 1, wherein a shorter side of said at least one substrate is 20 cm or more. 
     
     
       6. The thin-film-coated substrate manufacturing method according to claim 1, wherein the at least one substrate is unwound from a substrate roll. 
     
     
       7. The thin-film-coated substrate manufacturing method according to claim 6, wherein a width of the at least one substrate is 20 cm or more. 
     
     
       8. The thin-film-coated substrate manufacturing method according to claim 1, wherein an angle formed by a straight line connecting a location of any of the at least one film formation monitor plate and any of the at least one generating source and a normal line to a monitoring film formation surface on any of the at least one film formation monitor is in a range of 400 or less. 
     
     
       9. The thin-film-coated substrate manufacturing method according to claim 1, wherein said at least one film formation monitor plate is one of a plurality of film formation monitor plates and the step of monitoring includes monitoring one of said plurality of film formation monitor plates until a first thickness is detected and then monitoring another of said plurality of film formation monitor plates until a second thickness is detected. 
     
     
       10. The thin-film-coated substrate manufacturing method according to claim 1, wherein said step of coating includes adjusting a length of the film formation area in the pathway of said at least one substrate. 
     
     
       11. The thin-film-coated substrate manufacturing method according to claim 1, wherein said step of coating includes controlling a passing through speed of said at least one substrate inside the film formation area. 
     
     
       12. The thin-film-coated substrate manufacturing method according to claim 1, wherein said step of coating includes controlling a quantity of film-forming particles reaching the film formation area per unit time. 
     
     
       13. The thin-film-coated substrate manufacturing method according to claim 1, wherein said step of coating includes controlling according to a surface temperature of said at least one substrate. 
     
     
       14. The thin-film-coated substrate manufacturing method according to claim 1, wherein said step of coating includes controlling a film formation speed based on the thickness of the monitoring film measured. 
     
     
       15. The thin-film-coated substrate manufacturing method according to claim 14, wherein said step of coating includes maintaining said film formation speed substantially constant. 
     
     
       16. The thin-film-coated substrate manufacturing method according to claim 1, wherein said step of generating the film-forming particles is at least one of vacuum evaporation, ion plating, sputtering or ablation. 
     
     
       17. The manufacturing method according to claim 1, wherein the at least one film formation monitor plate is affixed within the exposure and adjacent to the film formation area. 
     
     
       18. The manufacturing method according to claim 1, wherein the at least one film formation monitor plate is displaceable within the exposure area. 
     
     
       19. The manufacturing method according to claim 2, wherein the film formation area has a shape defined by four sides, where one pair of sides is substantially linear while another pair of sides is substantially concavely curved. 
     
     
       20. A thin-film-coated substrate manufacturing system comprising: at least one film-forming particle beam generating source;   means for moving at least one substrate to be coated along a pathway through an exposure area including a film formation area, said film formation area including a surface of the at least one substrate and a surface of said moving means, said exposure area being exposed to a film-forming particle beam generated by the at least one film-forming particle beam generating source, said beam including a central axis;   at least one optical interference film measuring device, said at least one film-forming particle beam generating source being controlled in accordance with data from said at least one optical interference film measuring device; and   at least one optical interference film formation monitor plate, said measuring device measures light intensity and color of light reflected from said monitor plate, the at least one film formation monitor plate is either (i) affixed within the exposure area and outside the film formation area and outside said central axis of said beam; or   (ii) displaceable within the exposure area and within said central axis of said beam, whereby a correlation of the film thickness disposed on the at least one affixed or displaceable monitoring plate relative to a film thickness disposed on the at least one substrate is substantially maximized, wherein a distance from the at least one optical interference monitor plate the at least one generating source is in a range of 0.9 times or more of a first distance from the at least one generating source to the closest point thereto in the film formation area and 1.1 times or less of a second distance from the at least one generating source to the farthest point therefrom in the film formation area; or       a first angle formed by a straight line connecting a location of the at least one film formation monitor plate and the at least one generating source and a film-forming particle beam axis is in a range of twice or less than a second angle formed by a straight line connecting the at least one generating source and the farthest point therefrom in the film formation area and the film-forming particle beam axis thereof.   
     
     
       21. The thin-film-coated substrate manufacturing system according to claim 20, wherein said at least one substrate is a plurality of substrates. 
     
     
       22. The thin-film-coated substrate manufacturing system according to claim 20, wherein the means for moving at least one substrate includes substrate rolls. 
     
     
       23. The thin-film-coated substrate manufacturing system according to claim 20, wherein the angle formed by a straight line connecting a location of any of the at least one film formation monitor plate and any of the at least one generating source and a normal line to a monitoring film formation surface on any of the at least one film formation monitor plate is in a range of 40° or less. 
     
     
       24. The thin-film-coated substrate manufacturing system according to in claim 20, wherein said at least one film formation monitor plate is one of a plurality of film formation monitor plates and further comprising means for producing thin films by controlling film coating based on a thickness of monitoring films formed on said plurality of film formation monitor plates. 
     
     
       25. The thin-film-coated substrate manufacturing system according to claim 20, which further comprises means for controlling film coating by adjusting a length of the exposure area along the pathway in a movement direction of said at least one substrate. 
     
     
       26. The thin-film-coated substrate manufacturing system according to claim 20, further comprises means for controlling a speed of movement of said at least one substrate in the exposure area. 
     
     
       27. The thin-film-coated substrate manufacturing system according to claim 20, which further comprises means for controlling a quantity of film-forming particles reaching the exposure area per unit time. 
     
     
       28. The manufacturing apparatus according to claim 20, wherein the at least one film formation monitor plate is affixed within the exposure and adjacent to the firm formation area. 
     
     
       29. The manufacturing apparatus according to claim 20, wherein the at least one film formation monitor plate is displaceable within the exposure area.